The present invention relates to electronic devices and more particularly to a touch screen input technique for allowing a user input to an electronic device having a touch screen.
Advances in technology have resulted in smaller and more sophisticated electronic devices becoming available. These devices, such as portable communication devices, allow a user wireless access to communication networks, thereby enabling both Internet access and two-way e-mail communication.
As the size of these communication devices decreases and as the number of functions increases, it has become increasingly important for a user to be able to enter commands and information into the communication device in an efficient manner. With a reduction in size of the device, a keypad input device must also be reduced in size, thereby decreasing the efficiency with which information can be inputted by reducing the number and size of the keys. Furthermore, with a reduction in size of the device, the display size must also be reduced. Still furthermore, the use of a mouse with such devices is usually not possible since a mouse requires a flat clean surface to be properly used.
The use of a touch screen input device that serves both as a display and as an input device for the communication device allows a larger display in that a large keypad is no longer required since many of the functions have been taken over by the use of the display screen as an input device. A user enters information and data by touching the display screen at specific points.
U.S. Pat. No. 4,700,022 to Salvador et al. is directed to a method an apparatus for determining the coordinates of a contact point on a resistive type semi-analog sensitive surface. The coordinates are of a zone of contact of a conductive object, such as a finger, on a sensitive surface consisting of an insulating support having a grate formed by two terminals between which a certain number of emitting resistant strips are connected in parallel and having detecting conductive strips placed between the resistant strips. This patent merely discloses one of many techniques for determining the location of the zone of contact on a touch sensitive screen.
U.S. Pat. No. 5,119,079 to Hube et al. is directed to a touch screen user interface with expanding touch locations for a reprographic machine. The interface allows the expansion of the area for selection on the touch screen so as to improve the accuracy of selection thereof.
U.S. Pat. No. 5,545,857 to Lee et al. is directed to a remote control device having a touch screen allowing user input via the touch screen.
While each of the three above-noted patents discloses the use of a touch screen for inputting purposes, none of these patents teaches or suggests a touch screen arrangement in which both the location and the time duration and/or pressure and/or velocity of a finger or other object contacting the touch screen are detected, the detected values being quantized so as to allow the dragging and dropping of an item displayed on the touch screen.
An object of the present invention is to provide a touch screen technique for an electronic device, for example, which allows such electronic device to have a reasonably large display screen in a compact configuration. The keypad of the device or substantial portions of the keypad of the device are deleted and their functions implemented by the touch screen display screen, thereby allowing more space to be utilized for the display screen.
Another object of the present invention is to provide a touch screen technique for an electronic device in which the location and the time duration of an object, such as a finger or stylus or other pointed object, contacting or pressing a detection point on the touch screen, are detected. In addition, the pressure of the object on the touch screen may be detected as well as the velocity of the object as it is moved across the face of the touch screen. The detected time duration may be quantized into one of two or more values, each value corresponding to a specific input state. The interpretation of the contact detection may be dependent on the application and/or program phase active in the electronic device. For example, pressing a selection point for a first predetermined time period may correspond to single clicking the left button on a mouse. On the other hand, pressing a selection point for a second predetermined period of time which is longer than the first predetermined period of time may correspond to double-clicking the left button on a mouse. Thus, when a touch input is effected by pressing a selected first item displayed on the touch screen for a predetermined period of time and then dragging the object or finger along the face of the touch screen to a second item displayed on the touch screen while pressing the screen with a lighter pressure than the initial pressing on the selected first item and then pressing on the second item displayed on the touch screen for a third predetermined period of time may result in moving the selected item to the location of the second item, that is, dragging and dropping the selected first item on the second item.